Cutter attachment for sewing machines



A. E. ALLWES June 20, 1967 CUTTER ATTACHMENT FOR SEWING MACHINES Filed Sept. 21: 1964 Fig.5.

INVENTOR. ALVIN E. ALLWES his ATTORNEY 3,326,154 CUTTER ATTACHMENT FOR SEWING MACHINES Alvin E. Allwes, 519 Woodbourne Ave., Pittsburgh, Pa. 15226 Filed Sept. 21, 1964, Ser. No. 397,847 2 Claims. (Cl. 112-128) This invention relates to an attachment for sewing machines and, more particularly, to a knife attachment for cutting the edge portion of cloth by means of the reciprocating movements of the sewing machine needle bar.

In the past, cutter attachments have been used in sewing machines for the purpose of cutting cloth. However, such attachments have invariably been extremely complicated in construction and expensive to manufacture and maintain, therefore, have not been widely adopted commercially.

An object of my invention is to overcome the abovementioned disadvantages of conventional cutter attachments for sewing machines by providing an attachment which is extremely simple in construction, having a minimum number of inexpensive parts to an assembly which is easily and detachably mounted on the presser foot in a manner so as to enable reciprocation of the cutter by the movements of the sewing machine needle bar or holder.

Other objects and advantages of the invention will become more apparent from the following description taken with the accompanying drawing wherein:

FIG. 1 is an elevational view of a fragmentary part of a sewing machine including the presser foot and needle assemblies;

FIG. 2 is a cross-sectional view taken along line II- II of FIG. 1;

FIG. 3 is a plan view taken along line IIIIII of FIG. 1;

FIG. 4 is a view similar to FIG. 1 except showing the cutter attachment moved to the downward position by the needle bar; and

'FIG. 5 is an enlarged perspective view of the cutter attachment shown in FIGS. 1, 2, and 4.

Referring more particularly to the drawing, numeral 1 generally denotes the head of a sewing machine of any conventional type, including a vertically reciprocable portion 2 for mounting a needle bar 3 to effect vertical reciprocation of a needle (not shown). A presser foot and bar 4 is shown including a modified foot portion 11, 12 attached to the threaded shaft of presser foot bar 4 by nut 9 and provided with a central slot and on which presser foot bar is detachably mounted a cutter attachment, denoted generally by numeral 6 and shown more clearly in FIG. 5.

Referring to FIG. 5 which shows a cutter attachment embodying the principles of the present invention, numeral 7 denotes a clamp and numeral 8 denotes a screw for detachably securing the cutter attachment to the presser foot bar 4. A strip of spring metal 13 is provided with a central slot (not shown) which straddles the presser foot bar 4 and which is superimposed on the foot portion 11, 12. On the extremity of the strip or leaf spring 13 there is mounted a cutter holder 14 comprising two portions connected together by a bolt 15, which portions are attached to the end portion of spring 13 by means of screws 18. Tightly sandwiched between the portions ed States Patent Office 3,326,154 Patented June 20, 1967 14 by bolt 15 is a blade or knife 16 which is disposed at an angle and which projects through the slot in the presser foot and through a registering slot in the base plate 19 of the sewing machine. Alongside such slot, as shown in FIG. 3, are two conventional toothed elements or dogs 21 for feeding the cloth as it is being sewn.

In operation, the needle of the sewing machine is first removed and the cutter attachment 6 is mounted on the presser foot so that the knife or blade 16 projects through the central slot formed in the presser foot and through the registering slot 20 formed in the base plate 19. Thus as the needle bar 13 is vertically reciprocated by the sewing machine mechanism, in the conventional way, the bottom end portion of the needle bar 3 will push against and actuate the leaf spring 13 and effect flexing movements or oscillations thereof in a vertical plane, and in so doing, the cutter 16 will out the longitudinal edge portion of cloth as it is being fed by the dogs 21 located in the throat plate 5 of the sewing machine, which dogs are actuated by the sewing machine mechanism. As shown in FIG. 4 as the needle bar 23 is moved downwardly so as to flex leaf spring 13 vertically in an arcuate path, the knife 16 will correspondingly be moved downwardly to effect an arcuate cutting stroke, and as the needle bar 23 is lifted, the action of the spring 13 will eflfect vertical lifting movement of the cutter 16, and in this manner effect vertical oscillations of cutter 16, which, in turn, will cut the edge portion of the cloth.

It will be noted that the blade 16 provides shearing action and is guided by being slidable against the edge of the central slot in base plate 19, as shown more clearly in FIG. 3.

If desired, the needle need 'not be removed from the needle bar 3 to effect cutting by the attachment so long as a slot 17 is provided in the leaf spring 13 through which the needle may pass. Care must be exercised to make sure that the needle is offset with respect to the blade in a lateral direction.

Thus it will be seen that I have provided an efficient cutter attachment which is detachably mounted on the presser foot of a sewing machine and which is actuated or vibrated by reciprocating movements of the needle bar, either while the needle is mounted or removed from the bar; furthermore, I have provided a cutter attachment comprised of only a few simple and inexpensive parts, but which is nevertheless very effective to cut cloth.

While I have illustrated and described a single embodiment of my invention, it will be understood that it is by -way of illustration only, and that various changes and modifications may be made within the contemplation of my invention and within the scope of the following claims.

I claim:

1. In combination with a sewing machine having a base plate, presser foot, presser foot bar and reciprocable needle bar, a cutter attachment detachably mounted on said presser foot bar, said attachment including spring means having one end portion attached to said presser foot bar actuated by said needle bar, and including a cutting blade constituting the sole cutting means and which is mounted on the free end portion of said spring means and projecting through a slot in said base plate so as to oscillate said blade vertically and arcuately in a vertical plane and effect cutting of cloth.

2. In combination with a sewing machine having a base plate, presser foot, presser foot bar and reciprocable needle bar, a cutter attachment detachably mounted on said presser foot bar, said attachment including a leaf spring having one end detachably fastened to said presser foot bar so as to oscillate the free end portion of said spring vertically in an arcuate path as the result of reciprocation of said needle bar and a cutting blade, constituting the sole cutting means and which is mounted on the free end portion of said leaf spring, said base plate having a slot and said presser foot having a registering slot through which slots said cutter blade projects so as to cut cloth as the result of reciprocation by said needle bar.

References Cited UNITED STATES PATENTS Tapley 1l2128 Glanville 112128 Warren 112128 Weinbach et a1. l12128 Alifano et a1 112-128 JORDAN FRANK-LIN, Primary Examiner.

H. H. HUNTER, Assistant Examiner. 

1. IN COMBINATION WITH A SEWING MACHINE HAVING A BASE PLATE, PRESSER FOOT, PRESSER FOOT BAR AND RECIPROCABLE NEEDLE BAR, A CUTTER ATTACHMENT DETACHABLY MOUNTED ON SAID PRESSER FOOT BAR, SAID ATTACHMENT INCLUDING SPRING MEANS HAVING ONE END PORTION ATTACHED TO SAID PRESSER FOOT BAR ACTUATED BY SAID NEEDLE BAR, AND INCLUDING A CUTTING BLADE CONSTITUTING THE SOLE CUTTING MEANS AND WHICH IS MOUNTED ON THE FREE END PORTION OF SAID SPRING MEANS AND PROJECTING THROUGH A SLOT IN SAID BASE PLATE SO AS TO OSCILLATE SAID BLADE VERTICALLY AND ARCUATELY IN A VERTICAL PLANE AND EFFECT CUTTING OF CLOTH. 